Organosilicon compounds

ABSTRACT

Organosilicon compounds each having in a molecule (A) a perfluoroalkyl group of at least 3 carbon atoms which may be separated by an etheric oxygen atom, (B) a monovalent hydrocarbon group containing a carboxylic acid anhydride structure, and (C) a hydrosilyl (SiH) group are novel and added to thermosetting elastomer compositions as adhesion aids whereby the compositions are improved in adhesion to various materials including metals, alloys, plastics, and ceramics.

BACKGROUND OF THE INVENTION

1. Technical Field

This invention relates to novel organosilicon compounds which are added to various thermosetting elastomer compositions as adhesive aids.

2. Background Art

Known adhesive aids added to conventional thermosetting elastomer compositions include those having alkoxysilyl groups, acid anhydride groups and SiH groups. Although some adhesive aids achieve good adherence, there is a desire to have compounds more effective as adhesive aids.

SUMMARY OF THE INVENTION

It has been found that organosilicon compounds having in a molecule (A) a perfluoroalkyl group of at least 3 carbon atoms which may be separated by an etheric oxygen atom, (B) a monovalent hydrocarbon group containing a carboxylic acid anhydride structure, and (C) a hydrosilyl group are effective as adhesive aids, especially as adhesive aids in elastomer compositions containing fluorinated compounds for enhancing their adhesion to metals.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The organosilicon compound of the invention has in a molecule (A) a perfluoroalkyl group of at least 3 carbon atoms which may be separated by an etheric oxygen atom, (B) a monovalent hydrocarbon group containing a carboxylic acid anhydride structure, and (C) a hydrosilyl (SiH) group.

Specifically, the organosilicon compound has the average compositional formula (1) and preferably the general formula (2), (3) or (4).

 Rf_(a)R¹ _(b)R² _(c)H_(d)SiO_((4−a−b−c−d)/2)  (1)

In formula (1), Rf is a monovalent organic group containing a perfluoroalkyl group of at least 3 carbon atoms which may be separated by an etheric oxygen atom,

R¹ is a substituted or unsubstituted monovalent hydrocarbon group,

R² is a monovalent hydrocarbon group containing a carboxylic acid anhydride structure,

a, b, c and d are numbers satisfying:

0.01≦a≦50.5, preferably 0.05≦a≦0.3,

0≦b≦2, preferably 0.5≦b≦1.5,

0.01≦c≦0.5, preferably 0.05≦c≦0.3,

0.01≦d≦0.5, preferably 0.05≦d≦0.3, and

2≦a+b+c+d≦3.

In formula (2), R³ is a substituted or unsubstituted divalent hydrocarbon group,

R⁴ and R⁵ each are a substituted or unsubstituted monovalent hydrocarbon group,

R⁶ is independently hydrogen, Rf, R¹ or R², wherein Rf, R¹ and R² are as defined above, at least one hydrogen, at least one Rf and at least one R² are contained in a molecule, and

e is an integer of 0 or 1.

In formula (3), R⁴ is a substituted or unsubstituted monovalent hydrocarbon group; R⁶ is independently hydrogen, Rf, R¹ or R², wherein Rf, R¹ and R² are as defined above; at least one hydrogen, at least one Rf and at least one R² are contained in a molecule; and m is a positive integer of at least 3 and preferably 3 to 8.

In formula (4), R⁴ is a substituted or unsubstituted monovalent hydrocarbon group; R⁶ is independently hydrogen, Rf, R¹ or R², wherein Rf, R¹ and R² are as defined above; at least one hydrogen, at least one Rf and at least one R² are contained in a molecule; n is a positive integer of at least 1, preferably 1 to 500 and more preferably 5 to 200; and R⁷ is R⁴ or a group of the following formula (5):

wherein R⁴ and R⁶ are as defined above.

More illustratively, the substituted or unsubstituted monovalent hydrocarbon groups represented by R¹, R⁴ and R⁵ are preferably those of 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms, for example, alkyl groups such as methyl, ethyl and propyl, cycloalkyl groups such as cyclohexyl, aryl groups such as phenyl and tolyl, and the foregoing groups in which some hydrogen atoms are substituted with halogen atoms.

The monovalent hydrocarbon group containing a carboxylic acid anhydride structure, represented by R², is not critical as long has it has a carboxylic acid anhydride structure. Groups of the following formula are preferred.

Herein R⁷ is a divalent hydrocarbon group having 1 to 15 carbon atoms, and especially 2 to 10 carbon atoms, for example, an alkylene or alkenylene group.

Illustrative examples are given below.

The substituted or unsubstituted divalent hydrocarbon groups represented by R³ are preferably those of 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms, for example, alkylene groups such as methylene, ethylene and propylene, cycloalkylene groups such as cyclohexylene, arylene groups such as phenylene, and the foregoing groups in which some hydrogen atoms are substituted with halogen atoms.

The monovalent organic groups containing a perfluoroalkyl group of at least 3 carbon atoms which may be separated by an etheric oxygen atom, represented by Rf, include

F(C_(x)F_(2x))CH₂CH₂—,

F(C_(x)F_(2x))CH₂CH₂CH₂—, and

F(C_(y)F_(2y)O)_(p)C_(z)F_(2z)—A—,

wherein x is 3 to 20, y is 1 to 4, z is 1 to 10, p is 1 to 100, y multiplied by p is at least 2, and A is a divalent organic group, for example, an alkylene group such as methylene, ethylene or propylene.

Illustrative, non-limiting examples of the organic groups represented by Rf are given below. Note that Me is methyl.

C₄F₉CH₂CH—

C₈F₁₇CH₂CH₂CH₂—

C₃F₇O(CF₂CF₂CF₂O) _(h)CF₂CF₂CH₂CH₂—(e.g., h=1 to 50)

F—(CF₂O)_(h)(CF₂CF₂O) _(i)CF₂CH₂CH₂—(e.g., h=1 to 50, i=1 to 50)

Illustrative examples of the organosilicon compounds according to the invention are given below. They are typical examples, and the inventive compounds are not limited thereto. Note that Me is methyl.

The organosilicon compounds of the invention can be synthesized, for example, by the following method. The starting compound is an organosilicon compound having fluorine-modified groups, represented by the formula:

Rf_(a)R¹ _(b)H_(d)SiO_((4−a−b−d)/2)

wherein Rf and R¹ are as defined above, and 0.01≦a≦0.5, 0≦b≦2, 0.01≦d≦0.5, and 2≦a+b+d≦3. By effecting addition or hydrosilylation reaction of an acid anhydride having an ethylenically unsaturated group to the organosilicon compound having fluorine-modified groups in the presence of a hydrosilylation catalyst such as a platinum complex compound, the end compound is obtainable.

The reaction temperature is usually about 50 to 150° C., preferably about 70 to 120° C. If necessary, the reactants are diluted with a solvent such as toluene, xylene or 1,3-bistrifluoromethylbenzene.

Most often, the organosilicon compounds of the invention are added to thermosetting elastomer compositions as adhesion aids whereby the compositions are improved in adhesion to various materials including metals and alloys such as aluminum, iron, stainless steel, nickel alloys, chromium alloys and copper alloys, plastics such as acrylic resins, nylon, PPS, PBT, PET, epoxy resins, polyimides and polyvinyl chloride, and ceramics such as alumina and silicon nitride.

EXAMPLE

Examples of the invention are given below by way of illustration and not by way of limitation. Me is methyl.

Example 1

A 300-ml four-necked flask equipped with a stirrer, thermometer, reflux condenser and dropping funnel was charged with 70.0 g of an organosilicon compound of structure (i) below and 35.0 g of 1,3-bistrifluoromethyl-benzene and heated to an internal temperature of 80° C.

Then, 0.02 g of a toluene solution of the complex of chloroplatinic acid with 1,3-divinyl-1,1,3,3-tetramethyl-disiloxane (concentration 0.5 wt % calculated as platinum metal) was added to the flask, and 14.0 g of allylsuccinic anhydride was added dropwise from the dropping funnel.

After the completion of dropwise addition, the reaction solution was ripened at 80° C. for one hour. After the consumption of allylsuccinic anhydride was confirmed by gas chromatography, the solution was cooled.

Thereafter, 1.0 g of activated carbon was added to the solution, which was stirred for one hour and filtered. The filtrate was stripped at 120° C./3 mmHg for removing the solvent, leaving 74.3 g of a colorless clear liquid (viscosity 335 cs, specific gravity 1.393, refractive index 1.389).

On analysis by ¹H-NMR, IR and elemental analysis, the liquid was identified to be the following compound (ii).

¹H-NMR

δ 60.25(s, Si—CH₃: 12H)

δ 60.75(m, Si—CH₂—: 4H)

δ 1.6 to 2.4(m, Si—CH₂—CH ₂—CH ₂—: 8H)

δ 2.63(m, CO—CH: 1H)

δ 3.18(m, CO—CH₂—: 2H)

δ 4.85(s, Si—H: 2H)

IR

1788, 1865 cm⁻¹ν_(C═O)

2170 cm⁻¹ν_(Si—H)

Elemental analysis C H O Si F Found (%) 31.7 3.2 13.5 13.3 38.3 Calcd. (%) 31.4 3.5 13.3 13.3 38.5

Example 2

A 300-ml four-necked flask equipped with a stirrer, thermometer, reflux condenser and dropping funnel was charged with 70.0 g of an organosilicon compound of structure (iii) below and 35.0 g of 1,3-bistrifluoromethyl-benzene and heated to an internal temperature of 80° C.

Then, 0.02 g of a toluene solution of the complex of chloroplatinic acid with 1,3-divinyl-1,1,3,3-tetramethyl-disiloxane (concentration 0.5 wt % calculated as platinum metal) was added to the flask, and 14.0 g of allylsuccinic anhydride was added dropwise from the dropping funnel.

After the completion of dropwise addition, the reaction solution was ripened at 80° C. for one hour. After the consumption of allylsuccinic anhydride was confirmed by gas chromatography, the solution was cooled.

Thereafter, 1.0 g of activated carbon was added to the solution, which was stirred for one hour and filtered. The filtrate was stripped at 120° C./3 mmHg for removing the solvent, leaving 75.2 g of a colorless clear liquid (viscosity 92 cs, specific gravity 1.375, refractive index 1.385).

On analysis by ¹H-NMR, IR and elemental analysis, the liquid was identified to be the following compound (iv).

¹H-NMR

δ 0.09(s, C—Si—CH ₃: 6H)

δ 0.16(s, H—Si—CH ₃: 12H)

δ 0.65(m, Si—CH ₂—CH₂—CH₂—: 2H)

δ 0.72(m, Si—CH ₂—CH₂—CF₂—: 2H)

δ 1.4 to 2.2(m, Si—CH₂—CH ₂—CH2— and Si—CH₂—CH ₂—CF₂—: 6H)

δ 2.52(m, CO—CH: 1H)

δ 3.01(m, CO—CH₂—: 2H)

δ 4.72(s, Si—H: 2H)

IR

1787, 1867 cm⁻¹ν_(C═O)

2133 cm⁻¹νSi—H

Elemental analysis C H O Si F Found (%) 32.2 3.8 11.1 13.6 39.3 Calcd. (%) 32.9 3.9 11.4 13.3 38.5

Example 3

A 300-ml four-necked flask equipped with a stirrer, thermometer, reflux condenser and dropping funnel was charged with 100.0 g of an organosilicon compound of structure (v) below (SiH group content 0.10 mol) and 50.0 g of 1,3-bistrifluoromethylbenzene and heated to an internal temperature of 80° C.

Then, 0.02 g of a toluene solution of the complex of chloroplatinic acid with 1,3-divinyl-1,1,3,3-tetramethyl-disiloxane (concentration 0.5 wt % calculated as platinum metal) was added to the flask, and 2.8 g (0.020 mol) of allylsuccinic anhydride was added dropwise from the dropping funnel.

After the completion of dropwise addition, the reaction solution was ripened at 80° C. for one hour. After the consumption of allylsuccinic anhydride was confirmed by gas chromatography, the solution was cooled.

Thereafter, 1.5 g of activated carbon was added to the solution, which was stirred for one hour and filtered. The filtrate was stripped at 120° C./3 mmHg for removing the solvent, leaving 95.3 g of a colorless clear liquid (viscosity 25,000 cp, specific gravity 1.664, refractive index 1.343).

On analysis by ¹H-NMR, IR and elemental analysis, the liquid was identified to be the following compound (vi).

Note that of five R′ groups, on the average, four are R′=H, and one is

¹H-NMR

δ 0.09(S, C—Si—CH ₃: 12H)

δ 0.16(s, H—Si—CH ₃: 24H)

δ 0.31(s, arom.—Si—CH ₃: 6H)

δ 0.6 to 1.3(m, Si—CH ₂—: 10H)

δ 1.4 to 2.2(m, Si—CH₂—CH ₂—CH ₂—: 4H)

δ 2.52(m, CO—CH: 1H)

δ 3.01(m, CO—CH₂—: 2H)

δ 3.23(s, N—CH₃: 3H)

δ 4.72(s, Si—H: 4H)

δ 7.2 to 7.7(m, arom.: 4H)

IR

1788, 1865 cm⁻¹ν_(C═O)

2130 cm⁻¹ν_(Si—H)

Elemental analysis C H O Si F N Found (%) 25.4 1.3 10.8 5.1 57.1 0.3 Calcd. (%) 25.7 1.4 10.9 5.0 56.7 0.3

Japanese Patent Application No. 2000-306309 is incorporated herein by reference.

Although some preferred embodiments have been described, many modifications and variations may be made thereto in light of the above teachings. It is therefore to be understood that the invention may be practiced otherwise than as specifically described without departing from the scope of the appended claims. 

What is claimed is:
 1. An organosilicon compound having the average compositional formula (1): Rf_(a)R¹ _(b)R² _(c)H_(d)SiO_((4−a−b−c−d)/2)  (1) wherein Rf is a monovalent organic group containing a perfluoroalkyl group of at least 3 carbon atoms which may be separated by an etheric oxygen atom, R¹ is a substituted or unsubstituted monovalent hydrocarbon group, R² is a monovalent hydrocarbon group containing a carboxylic acid anhydride structure, and a, b, c, and d are numbers satisfying the relationships 0.01≦a≦0.5, 0≦b≦2, 0.01≦c≦0.5, 0.01≦d≦0.5, and 2≦a+b+c+d≦3.
 2. An organosilicon compound having the general formula (2):

wherein Rf is a monovalent organic group containing a perfluoroalkyl group of at least 3 carbon atoms which may be separated by an etheric oxygen atom, R¹ is a substituted or unsubstituted monovalent hydrocarbon group, R² is a monovalent hydrocarbon group containing a carboxylic acid anhydride structure, R³ is a substituted or unsubstituted divalent hydrocarbon group, R⁴ and R⁵ each are a substituted or unsubstituted monovalent hydrocarbon group, R⁶ is independently hydrogen, Rf, R¹, or R², at least one hydrogen, Rf, and R² each being contained in a molecule, and e is an integer of 0 or
 1. 3. An organosilicon compound having the general formula (3) or (4):

wherein R⁴ is a substituted or unsubstituted monovalent hydrocarbon group; Rf is a monovalent organic group containing a perfluoroalkyl group of at least 3 carbon atoms which may be separated by an etheric oxygen atom, R¹ is a substituted or unsubstituted monovalent hydrocarbon group, R² is a monovalent hydrocarbon group containing a carboxylic acid anhydride structure, R⁶ is independently hydrogen, Rf, R¹, or R², at least one hydrogen, Rf, and R² each being contained in a molecule; and m is a positive integer of at least 3, and

 wherein R⁴ is a substituted or unsubstituted monovalent hydrocarbon group; Rf is a monovalent organic group containing a perfluoroalkyl group of at least 3 carbon atoms which may be separated by an etheric oxygen atom, R¹ is a substituted or unsubstituted monovalent hydrocarbon group, R² is a monovalent hydrocarbon group containing a carboxylic acid anhydride structure, R⁶ is independently hydrogen, Rf, R¹, or R², at least one hydrogen, Rf, and R² each being contained in a molecule; n is a positive integer of at least 1; and R⁷ is R⁴ or a group of the following formula (5):

 wherein R⁴ and R⁶ are as defined above.
 4. The organosilicon compound of claim 1, wherein Rf is F(C_(x)F_(2x))CH₂CH₂—, F(C_(x)F_(2x))CH₂CH₂CH₂—, or F(C_(y)F_(2y)O)_(p)C_(z)F_(2z)—A— in which x is 3 to 20, y is 1 to 4, z is 1 to 10, p is 1 to 100, y multiplied by p is at least 2, and A is a divalent alkylene group, R¹ has 1 to 8 carbon atoms, and R² is a group of the formula

 wherein R⁷ is a divalent hydrocarbon group having 2 to 10 carbon atoms.
 5. The organosilicon compound of claim 3, wherein Rf is F(C_(x)F_(2x))CH₂CH₂—, F(C_(x)F_(2x))CH₂CH₂CH₂—, or F(C_(y)F_(2y)O)_(p)C_(z)F_(2z)—A— in which x is 3 to 20, y is 1 to 4, z is 1 to 10, p is 1 to 100, y multiplied by p is at least 2, and A is a divalent alkylene group, R¹ has 1 to 8 carbon atoms, and R² is a group of the following formula wherein R⁷ is a divalent hydrocarbon group having 2 to 10 carbon atoms

R³ has 1 to 8 carbon atoms, R⁴ has 1 to 8 carbon atoms, and R⁵ has 1 to 8 carbon atoms.
 6. The organosilicon compound of claim 3, having the formula (3) wherein R⁴ is a substituted or unsubstituted monovalent hydrocarbon group of 1 to 8 carbon atoms; Rf is a monovalent organic group containing a perfluoroalkyl group of at least 3 carbon atoms which may be separated by an etheric oxygen atom, R¹ is a substituted or unsubstituted monovalent hydrocarbon group of 1 to 8 carbon atoms, R² is a monovalent hydrocarbon group containing a carboxylic acid anhydride structure, R⁶ is independently hydrogen, Rf, R¹, or R², at least one hydrogen, Rf, and R² each being contained in a molecule; and m is a positive integer of at least
 3. 7. The organosilicon compound of claim 3, having the formula (4) wherein R⁴ is a substituted or unsubstituted monovalent hydrocarbon group of 1 to 8 carbon atoms, Rf is a monovalent organic group containing a perfluoroalkyl group of at least 3 carbon atoms which may be separated by an etheric oxygen atom, R¹ is a substituted or unsubstituted monovalent hydrocarbon group of 1 to 8 carbon atoms, R² is a monovalent hydrocarbon group containing a carboxylic acid anhydride structure, R⁶ is independently hydrogen, Rf, R¹, or R², at least one hydrogen, Rf, and R² each being contained in a molecule; n is a positive integer of at least 1; and R⁷ is R⁴.
 8. The organosilicon compound of claim 3, having the formula (4) wherein R⁴ is a substituted or unsubstituted monovalent hydrocarbon group of 1 to 8 carbon atoms, Rf is a monovalent organic group containing a perfluoroalkyl group of at least 3 carbon atoms which may be separated by an etheric oxygen atom, R¹ is a substituted or unsubstituted monovalent hydrocarbon group of 1 to 8 carbon atoms, R² is a monovalent hydrocarbon group of containing a carboxylic acid anhydride structure, R⁶ is independently hydrogen, Rf, R¹, or R², at least one hydrogen, Rf, and R² each being contained in a molecule; n is a positive integer of at least 1; and R⁷ is a group of the formula (5):

 wherein R⁴ and R⁶ are as defined above. 